The group are understood to have been in Africa writing songs for the follow-up to 2004's How To Dismantle An Atomic Bomb.
They have been joined by long-term collaborators Eno and Daniel Lanois, who have produced some of their most important recordings.
In an online posting, Bono explained how sessions were coming along. "We have no plans for the music yet. We're just going to make it until we can't not put it out!"
Meanwhile, Larry Mullen commented on U2's official website: "It's the first time we've worked with Brian and Dan in a purely songwriting capacity. So it's very different, quite experimental and kind of liberating because of that."
The last "original" piece of music released by U2 was "The Saints Are Coming," a cover of the Skids' classic with Green Day, which was produced by Rick Rubin.
U2 tour tops annual rankings in North America
Dec 30, 2009 6:02 pm PST
U2 may have suffered disappointing sales for their new album, but the Irish rockers were easily the most popular draw on the North American concert circuit this year, according to data issued on Wednesday. The band sold $123 million...
U2 to headline UK's Glastonbury music festival
Nov 23, 2009 3:00 am PST
Organizers say U2 will headline Glastonbury, Britain's leading summer music festival. Festival boss Michael Eavis said Monday that the Irish rockers will play the festival's main stage on June 25. It will be U2's first...
Outrage over wall blocking free U2 Berlin concert
Nov 5, 2009 2:00 pm PST
Irish rockers U2 returned to Berlin for a free mini-concert Thursday in front of the Brandenburg Gate, playing its classic singles and a duet with Jay-Z even as the show was obscured from public view by a nearly 6-1/2-foot (two-meter) high...
U2 concert is YouTube's largest streaming event
Oct 29, 2009 11:00 am PDT
YouTube's webcast of a U2 concert was watched by nearly 10 million people, the video site's largest streaming event ever. The Google Inc.-owned site said that the concert was watched around the world. It was shown live ...
U2 to play free show to mark fall of Berlin Wall
Oct 27, 2009 7:00 pm PDT
Achtung, baby: U2 will play a free concert in Berlin to help the city celebrate 20 years since the fall of the Berlin Wall. Music network MTV said the Irish rockers will perform in front of the Brandenburg Gate on Nov. 5 during the MTV Eu...